6 ms·

A.k.a series hybrid. Chevy attempted this with the Volt - it made perfect sense to me but never really caught on.

theshrike79 4y ago
I don't understand why series hybrids didn't catch on. They were a complete no-brainer to me (not a car engineer though). With a regular hybrid you need to have complex clutch arrangements to transfer power from two engines to the wheels simultaneously. In a series hybrid you'd have a fully electric drivetrain and a fuel powered generator, that could always run at optimal efficiency.
- WorldMaker 4y ago
  The series hybrid is still more complexity over a fully battery electric. More weight especially. The density/size/weight trade-off of carrying around a gas generator at all times versus how much additional battery you can add for that same weight and better size (because increased density) kind of generally makes gas generators less desirable than just adding more batteries to a simpler battery electric. I have a ten year old Chevy Volt that I still love and it was a great transitionary option when I bought it ten years ago. I still think it was the right choice for me at the time. At this point, I feel like the age of the series hybrid is already "over", not just because the Volt was discontinued, but because full battery electrics have only gone on to prove their simplicity, what they can do with larger batteries, and everything about the improvements in 10 years of EV development. I wish other people had as an easy of a transition as I had, but I also think that it's better for everyone to just dive in with a full EV rather than a (good for the time, but bad today) compromise like a series hybrid.
- Gibbon1 4y ago
  The parallel hybrids are really genius. At the heart of the Prius design is a simple planetary gear and two eletric motors that forms a power split device. What makes it different from a normal planetary gear train is you have a motor generator MG1 on the engine and MG2 one the ring gear. The deal is you have a mechanical power path via the planetary gears. And you have a parallel electric power path between MG1 and MG2 (and the battery). In the end it's a just a CVT. It's conceptually more complicated, but probably not in practice.
  - theshrike79 4y ago
    Yeah, the Prius eCVT really spoiled me for any other style of power transfer. Even the smoothest automatic felt like crap after it. So, naturally, the only choice upwards from there was fully electric for me =)
- fomine3 4y ago
  Series hybrid (not pluggable) is now become popular here in Japan, like Nissan Note, Honda Fit, Daihatsu Rocky, and even minivans. Pros is that the mechanism is similar to BEV so not much R&D cost, and efficiency in city use. Cons is highway fuel efficiency (and lower power than pure ICE) but people not tend to drive highway frequently like US. BEVs are still far from affordable for average Japanese income for now, and plenty of people can't have outlet for rented parking.
  - KennyBlanken 4y ago
    It's worth noting that the reason hybrids are popular in Japan is due to Toyota pushing them, very heavily, due to their substantial failure to keep up innovation-wise and not invest in EV drivetrains and platforms. Toyota has gone so far as to print what amounts to propaganda for grade school children to brainwash them into the evils of BEVs. There is no reason BEVs wouldn't work in Japan. Extensive, highly reliable, fast public transit means range is irrelevant and vehicles can be small, light, with small batteries and small motors. High voltage means a normal wall socket and most circuits provide plenty of power for charging, no need for special circuit installs. BEVs are easier to produce, are a fraction as complicated, and have very little maintenance and long lifespan. That's another reason Japan doesn't have any interest in them; a massive part of Japan's economic engine is their regulating cars off the road after a shockingly short period of time to export them off to Rest of World (and the resulting parts sales...)
    - fomine3 4y ago
      Agree that BEV works in Japan and Japanese motor company (good at making ICE) have incentive to delay transition for BEV. Still, there are blockers to have EV in Japan. Having normal charging outlet on mechanical parking in Tokyo is difficult. Govt subsidy is now getting available but replacing entire mechanical parking system would be very costly. Non-pluggable hybrid is practical for them. Anyway they tend to not use cars for commute everyday, so they aren't best customer for BEV. BEV on local cities/rural areas (where most people use car for commute) is very practical especially they have a house, but they tend to not earn much so most BEVs are not affordable for now. They also love minivans that should be extremely optimized for inner space. Nissan Sakura is great for them as a second K-car on family. I wish Japanese manufacturers release more affordable models. Anyway (cheap and reliable) massive battery supply is the blocker for EV transition that should be solved by automotive company. Toyota can make 40x Prius for one bz4X battery capacity. > Extensive, highly reliable, fast public transit means range is irrelevant. You mean BEV for rental car fleet? It's different story. They care vehicle cost very much, but fuel price is paid by customer.
zerohp 4y ago
The Chevy Volt could operate as a series or parallel hybrid. So it didn't really save any design or build complexity.
- WorldMaker 4y ago
  It wasn't a true parallel hybrid in the Prius design sense, and it was only used in a peculiar series of events: it had a belt from the gas generator to help with power situations above normal highway speeds and/or torque in low battery situations or the provided Mountain mode (when concerned about steep inclines). The goal of that mode of parallel operation was to use as much weak torque power directly from the gas generator as possible (which had very weak torque) so that the system overall could save as much battery as absolutely possible so that in moments where you need high torque there was some spare battery for it. (On a steep incline on a mountain is absolutely when you don't want to run out of torque.) In most operation patterns the Volt was always serial in regular driving and just about never "parallel". (Depending on how you drive of course. Drivers that consistently and regularly drive 80mph or more would have a different experience.) Compared to a Prius there was considerable design/build complexity savings in the Volt serial design (that sometimes has a low torque parallel connection). Compared to a fully battery electric vehicle however, yeah the Volt was still super complex.
bsder 4y ago
The Volt died due to lack of marketing because GM didn't really didn't want to make it due to cost. The problem is that all the car manufacturers know that hybrid is a dead end. So, everybody wants to produce all-electric since all-electric is ridiculously cheaper to produce than hybrid or combustion engine cars. In the meantime, back in the real world, the infrastructure for all-electric is rolling out very slowly. This means that you need to be a short-distance (read: larger city) commuter who owns a house with a garage parking spot (read: stupidly expensive real estate because in/near larger city) in order to take advantage of having an electric car. So, nobody wants to roll the infrastructure out since that's expensive and there's no lock in. And the manufacturers don't want to roll out hybrids since those are a dead end. (Good example of the brain damage: The Oceanside train station in San Diego has a couple of electric parking slots. The first problem is that there are too few--every spot should be electric. Second, you are only nominally allowed to use them when you are actively charging. This, of course, is stupid since you're likely to hit your charge maximum sometime when you are 100 miles away by train. Third, there is no useful shuttle from anywhere to the train station so that you could put your car there as a freeway stop and "top up" while you go shop, eat, etc.)
- JJMcJ 4y ago
  I mention the millions of people who park on the street e.g. https://i1.wp.com/blog.spothero.com/wp-content/uploads/2017/07/brooklyn.jpg?resize=600%2C400 https://i1.wp.com/blog.spothero.com/wp-content/uploads/2017/... Or in older apartment buildings where the management will never pay the money to put in electric chargers. People look at me like I'm a fool for even saying this.

I don't understand why series hybrids didn't catch on. They were a complete no-brainer to me (not a car engineer though). With a regular hybrid you need to have complex clutch arrangements to transfer power from two engines to the wheels simultaneously. In a series hybrid you'd have a fully electric drivetrain and a fuel powered generator, that could always run at optimal efficiency.

WorldMaker 4y ago
The series hybrid is still more complexity over a fully battery electric. More weight especially. The density/size/weight trade-off of carrying around a gas generator at all times versus how much additional battery you can add for that same weight and better size (because increased density) kind of generally makes gas generators less desirable than just adding more batteries to a simpler battery electric. I have a ten year old Chevy Volt that I still love and it was a great transitionary option when I bought it ten years ago. I still think it was the right choice for me at the time. At this point, I feel like the age of the series hybrid is already "over", not just because the Volt was discontinued, but because full battery electrics have only gone on to prove their simplicity, what they can do with larger batteries, and everything about the improvements in 10 years of EV development. I wish other people had as an easy of a transition as I had, but I also think that it's better for everyone to just dive in with a full EV rather than a (good for the time, but bad today) compromise like a series hybrid.
Gibbon1 4y ago
The parallel hybrids are really genius. At the heart of the Prius design is a simple planetary gear and two eletric motors that forms a power split device. What makes it different from a normal planetary gear train is you have a motor generator MG1 on the engine and MG2 one the ring gear. The deal is you have a mechanical power path via the planetary gears. And you have a parallel electric power path between MG1 and MG2 (and the battery). In the end it's a just a CVT. It's conceptually more complicated, but probably not in practice.
- theshrike79 4y ago
  Yeah, the Prius eCVT really spoiled me for any other style of power transfer. Even the smoothest automatic felt like crap after it. So, naturally, the only choice upwards from there was fully electric for me =)
fomine3 4y ago
Series hybrid (not pluggable) is now become popular here in Japan, like Nissan Note, Honda Fit, Daihatsu Rocky, and even minivans. Pros is that the mechanism is similar to BEV so not much R&D cost, and efficiency in city use. Cons is highway fuel efficiency (and lower power than pure ICE) but people not tend to drive highway frequently like US. BEVs are still far from affordable for average Japanese income for now, and plenty of people can't have outlet for rented parking.
- KennyBlanken 4y ago
  It's worth noting that the reason hybrids are popular in Japan is due to Toyota pushing them, very heavily, due to their substantial failure to keep up innovation-wise and not invest in EV drivetrains and platforms. Toyota has gone so far as to print what amounts to propaganda for grade school children to brainwash them into the evils of BEVs. There is no reason BEVs wouldn't work in Japan. Extensive, highly reliable, fast public transit means range is irrelevant and vehicles can be small, light, with small batteries and small motors. High voltage means a normal wall socket and most circuits provide plenty of power for charging, no need for special circuit installs. BEVs are easier to produce, are a fraction as complicated, and have very little maintenance and long lifespan. That's another reason Japan doesn't have any interest in them; a massive part of Japan's economic engine is their regulating cars off the road after a shockingly short period of time to export them off to Rest of World (and the resulting parts sales...)
  - fomine3 4y ago
    Agree that BEV works in Japan and Japanese motor company (good at making ICE) have incentive to delay transition for BEV. Still, there are blockers to have EV in Japan. Having normal charging outlet on mechanical parking in Tokyo is difficult. Govt subsidy is now getting available but replacing entire mechanical parking system would be very costly. Non-pluggable hybrid is practical for them. Anyway they tend to not use cars for commute everyday, so they aren't best customer for BEV. BEV on local cities/rural areas (where most people use car for commute) is very practical especially they have a house, but they tend to not earn much so most BEVs are not affordable for now. They also love minivans that should be extremely optimized for inner space. Nissan Sakura is great for them as a second K-car on family. I wish Japanese manufacturers release more affordable models. Anyway (cheap and reliable) massive battery supply is the blocker for EV transition that should be solved by automotive company. Toyota can make 40x Prius for one bz4X battery capacity. > Extensive, highly reliable, fast public transit means range is irrelevant. You mean BEV for rental car fleet? It's different story. They care vehicle cost very much, but fuel price is paid by customer.

zerohp 4y ago

The Chevy Volt could operate as a series or parallel hybrid. So it didn't really save any design or build complexity.

WorldMaker 4y ago
It wasn't a true parallel hybrid in the Prius design sense, and it was only used in a peculiar series of events: it had a belt from the gas generator to help with power situations above normal highway speeds and/or torque in low battery situations or the provided Mountain mode (when concerned about steep inclines). The goal of that mode of parallel operation was to use as much weak torque power directly from the gas generator as possible (which had very weak torque) so that the system overall could save as much battery as absolutely possible so that in moments where you need high torque there was some spare battery for it. (On a steep incline on a mountain is absolutely when you don't want to run out of torque.) In most operation patterns the Volt was always serial in regular driving and just about never "parallel". (Depending on how you drive of course. Drivers that consistently and regularly drive 80mph or more would have a different experience.) Compared to a Prius there was considerable design/build complexity savings in the Volt serial design (that sometimes has a low torque parallel connection). Compared to a fully battery electric vehicle however, yeah the Volt was still super complex.

bsder 4y ago

The Volt died due to lack of marketing because GM didn't really didn't want to make it due to cost. The problem is that all the car manufacturers know that hybrid is a dead end. So, everybody wants to produce all-electric since all-electric is ridiculously cheaper to produce than hybrid or combustion engine cars. In the meantime, back in the real world, the infrastructure for all-electric is rolling out very slowly. This means that you need to be a short-distance (read: larger city) commuter who owns a house with a garage parking spot (read: stupidly expensive real estate because in/near larger city) in order to take advantage of having an electric car. So, nobody wants to roll the infrastructure out since that's expensive and there's no lock in. And the manufacturers don't want to roll out hybrids since those are a dead end. (Good example of the brain damage: The Oceanside train station in San Diego has a couple of electric parking slots. The first problem is that there are too few--every spot should be electric. Second, you are only nominally allowed to use them when you are actively charging. This, of course, is stupid since you're likely to hit your charge maximum sometime when you are 100 miles away by train. Third, there is no useful shuttle from anywhere to the train station so that you could put your car there as a freeway stop and "top up" while you go shop, eat, etc.)

JJMcJ 4y ago
I mention the millions of people who park on the street e.g. https://i1.wp.com/blog.spothero.com/wp-content/uploads/2017/07/brooklyn.jpg?resize=600%2C400 https://i1.wp.com/blog.spothero.com/wp-content/uploads/2017/... Or in older apartment buildings where the management will never pay the money to put in electric chargers. People look at me like I'm a fool for even saying this.